import 'dart:ffi';

void main() {
  dynamic phone = Phone("iphone13", 6000);
  Expando refer = Expando("phone");
  refer[phone] = true;
  print(refer[phone]);
  print("after gc");
  phone = null;
  print(refer[phone]);
}

class Phone {
  String name;
  double price;

  Phone(this.name, this.price);

  @override
  String toString() {
    return 'Phone{name: $name, price: $price}';
  }
}
